who is sephiroth father

[Raistlin]

I think it is Hojo, but still you can't completely dismiss the possibility, because the game doesn't really mention it as a fact... it just mentions it.

Oh, I see what you're saying. So even though the game says "Hojo is Sephiroth's father," you can't entirely dismiss other possibilities because it also didn't add "THIS IS A FACT" in bold letters next to it. Makes perfect sense.